Telephone system



A. E. LUNDELL.

TELEPHONE SYSTEM.

APPLICATION HLED 05c. 29. 1915.

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I H 5F" A. E. LUNDELL.

TELEPHONE SYSTEM.

APPLICATION FILED DEC. 29, 1916.

1,334,307. Patented Mar. 23,1920.

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A. E. LUNDELL.

TELEPHONE SYSTEM.

APPLICATION FILED DEC. 29, 1916.

1,334,307, Patented Mar. 23, 1920.

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A. E. LUNDELL.

TELEPHONE SYSTEM. APPLICATION FILED DEC. 29. I916.

Patented Mar. 23, 1920.

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//7 vema/r' Awe/7 AT lands/A y L Egg Lii lllNltiiED STATES PATENTOFFICE.

ALBEN E. LUNDELL, OF NEW YORK, N. 'Y., ASSIGNOB. TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NE? YORK, N. .A CORPORATION OF NEW' YORK.

TELEPHONE SYSTEM.

ii /"tom it may concern ino'v-i'n that 1, rininni l l. LUnnnLL, a if theUnited States, residing at lien 1 ers, in the county 01' Bronx and StateNew York, have invented certain new and useful lil'ii'Jl'OVhlllBl'lilSin Telephone Sys ow a, ct which. the following is a tull, clear,concise, and exact description.

This invention relates t sentiinutoinatic telephone systems, and moreparticularly to indicating arrangements employed in such tems.

in the pro ent arrangement, it the called line bus the operator has nomeans of iuumi'nn' whether the called line is at a local or at a distantexchange. This intorinatioiii is de irabie since, in order to ascertainnhether the initiated call is in that class known as revel-tire cells orin other words, :2 call originating on a party line to another aiscriiier on this party line, the operator must again ascertain thenumber from the calling subsc iber and compare this number with thenumber plate associated with the jack in which the calling plug has beeninsorted. It the called husy line is at a distant exchange, the operatorknows ionnediately that the call not revertive and it will beunnecessary for her, in this instance, to ;i. "-'in ascertain the numberoi": the called line.

The main feature of this invention is the provision of means to operateone signal at the exchange it the called busy line is at the i1)! :alenchan eye, and to operate a second signal at the same exchange it thecalled busy line is at adistant exchange.

in its specific embodiment, this invention consists ct r--thc provisionoi? two signals at one ot the offices of the system to indicate the busyor idle condition of called lines, an inter iptiug device at this oiiicefor controllinei .e operation 01'' one of aid signals, and

an interrupting device at a second office ot th s-iystein torcontrolling' the operation oi? the other signal, and a device at thefirst mentioned oiiice for controlling the operation of said signals.

The drawings, With Figure 2 placed below F with Fig. 3 placed below Fig.2, and. 1 Fig. placed at the right of Fig. 1, "uinaticall represent aportion of a yinn' the present invention. 1* i 1 diac inmaticallyrepresents a caliing line and a district selector through Specificationof Letters Patent- Patented Mar. 23, 1920.

Application filed December 25'. 1916.

Serial No. 139,514.

which the calling line will be extended. Fig. fs diagramnniuiticallyrepresents a cord finder.

3 diagrannnatically represents an opcintorl-i hey set and sendingdevice. The portion of the drawings to the left (if the dotted line inFig. 1 diagrannnatically repinsents an incoming selecting switch; theportion oi. the drawings shown to the right of the dotted line in Fig.4: diagraininatically represents a final selector switch. Both theincoming; and the final selector switches are located in the sameoflice, while the portion of the drawings of. Fig. 4. included withinthe dotted rectangle diagrannnatically indicates an incoming and a finalselector switch and an jii'itcrrunter located at a distant ofiicc.

in the present system a plurality of sequence switches are employedwhich are similar in structure to sequence switch disclosed in thepatent to Reynolds and Baldwin, No. 1,127,808, and are similar inoporation and tiniction to. the sequence switch disclosed in MellertyPatent No. 1,125,579. The contacts of any sequence switch are soparated- 'troin the other sequence switches e1nploycd. by the confines ofthe drawing and by dotted lines.

'llhe selecting switches employed in the system may be oil? a typedisclosed in patent to Craft and RGyHOldS, No. 1,123,696, J a11umy 5,1915, and the operating circuits for the si'i-itches are similar tothose disclosed in lahmt to Lundell, No. 1,168,819.

The p ent system also employs counting relays which are similar inari'nngemcnt and opeiation to those disclosed in the above mentionedtiatent to Lundell. No. 1,168,310. l or brevity in description, theregisters, which control the operation oi. the counting relays, andwhich are set by the depresF-sion oi? various keys in the key-setassociated with tlu: ope position. have been oiuitted. lit will beunderstood. however, that r as may be employed in the manner disiizlosedin the above mentioned patent to lnindell, No. 1,168,319.

When the subscriber at substation 105 removes his receiver from theswitch hook, the line relay 106 is energized over a circuit exti-indinetron; grounded battery, left I to ground. The line relay 106 attractsarmature and thereby completes a local circuit for lighting the lampsignal 108. The operator on noting the lighting of this sig nal insertsher answering plug 109 into the jack 110, of the calling line. A circuitis thus completed from grounded battery, winding of cut-oil relay 107,sleeve of jack 110, sleeve of plug 109, winding of relay 111, to ground.The relays 107 and 111 are energized and attract their armatures. Thecut-01f relay 107 interrupts the energizing circuit of line relay 106,which relay retracts its armature to open the local circuit of the lamp8. The relay 111 at its inner armature establishes a circuit from groundto inner armature and front contact of relay 111, contacts 101, 102,magnet of sequence switch 100, to grounded battery, to move the sequenceswitch out of position 1 and into position 2. In posi ion 2 of thesequence switch 100 an energizing circuit for the relay 216 is completedfrom grounded battery, winding of this relay, contacts 203 and 202,conductor 217, contact 103, to ground. Relay 216 attracts its armaturesand at its right-hand. armature and front contact completes a circuit inground through contact 20 magnet of sequence switch 200, to groundedbattery. This circuit causes the sequence switch 200 to move out ofposition 1 into position 2. In position 2 of the sequence switch 200 therelay 216 is maintained energized over a circuit extending from groundedbattery,

Winding of relay 216, contacts 208 and 215,

left-hand armature and back contact of the relay 219,to ground. Acircuit is completed for the up-drive magnet 218 of cord finder toassociate an idle sending device with the cordcircuit with which thecalling line has been connected. The operating circuit of therip-driving magnet 218 may be traced from grounded battery, windingjoimagnet 218, contact 205, front contact and right-hand armature of relay216, to ground. The cord finder elevates its brushes until the brush 221engages terminal 222, whereupon relay 219 is energized over the circuitfrom grounded battery, winding of the relay 219, contact 207, brush 221,terminal 222, contact 10%, to ground. Belay 219 is energized andattracts its arniatures.

At its right-hand armature and front contact it establishes a lockingcircuit for itself, which may be traced from grounded battery, windingof relay 219, contact 208, right-hand front contact and armature ofrelay 219, brush 224:, terminal 225, conductor 226, contacts 112, 113,righthand back contact and armature of relay 114, resistance to ground.This circuit maintains the relay 219 energized until district sc HQEICQswitch100 has moved out of position 2. At the left-hand armature andback contact of the relay 210, the energizing circuit of the relay 216is opened. It the brushes oi? the cord finder are properly centered onthe terminals the relay 216 deenergizes. Otherwise this relay will bemaintained energized over a circuit extending from grounded battery,contacts 203 and 206, conducting portion of the commutator 227,commutator brush 228, to ground. When the relay 216 is deenergized andat its right-hand trout contact and armature interrupts the operatingcircuit oi the up-driye magnet 210 to stop the cord finder switch, acircuit is al -o completed by the deenergization oi relay 216, formoving the sequence switch 200 out oi position 2 and into position 3.This eircuit may be traced from groiuidcd buttery, magnet of sequenceswitch 200, contact 200. right-hand back contact and armature of therelay 216, to ground. As soon as the scquence switch 200 reachesposition 3, a circuit is completed through contacts 2% and 311 formoving sequence switch 300 into position 3. After the operator insertedplug. 109 into jack 110 she depressed a listening hey 13-1 toteleydumically councct her head set (not shown) with the substation oithe calling subscriber. She then ascertains the number oi the desiredline and proceeds to set it up on the key set indicated at the right inFig. 3.

In the normal operation of the system the depression ol. :1. singleoilicc key control; the first two series of impulses and the romainingfive series oi? impulses are controlled by the depression of tour keys.In the present disclosure it has been deemed simpler to show seren setsof keys for controlling thc sending oil the scrcn series ol pulses.

ll hen the operator has set up the number on her keyboard she depressesa start key 303, which caus the sequence switch 200 to more out oi? posiion 3 and into position l, by a circuit completed from grounded buttery. magnet oi sequence switch 200, coutact 214., start key 303 toground. Simultaneously sequence switch 300 is moved out of position 3and into position 4-. The operating circuit for the sequence switch inthis instance extends from grounded battery. magnet of the sequenceswitch 300, contact 30d, start lzey 808 to ground.

The line relay is also energized at this time over a circuit which maybe traced from grounded battery, winding of line rolay 110, contacts116. 117. 118 and 11!), conductor 120, terminal 229. brush 2 30, conductor 232,. outer armature and bacl-r con tact of relay 309, winding ofstepping relay contact to ground. The line relay attracts its miniaturesand at its right-hand armature and front contact completes a lockingcircuit for it e f. which is not broken until sequence switch 100 leavesposition 5. This circuit may be traced from grounded battery, right-handWinding oil. line relay 1155, contact 121, right-hand tlfront contactand armature of relay 11.5 over the circuit previously described, toground at contact 815. At the left-hand front contact and armature ol.the line relay 115 a circuit is completed from grounded battery, ma; netof sequence switch 100, contacts 139 and 125, leithand front contact ofrelay 11.5,. left-hand back contact of relay 114: to ound for moving thesequence switch into position 8. In this position of sequence switch 100an energizing circuit for the updrive magnet 122 is completed fromground-- ed ba t ry Winding oil? magnet 192, conductor 123, contacts124: and 125, leitt-hand front contact and armature of line relay llti,left-hand back contact and armature o'l' relay 11411, to ground. As thedistrict selecting switch elevates its brushes over the terminals of hetrunks terminating at the snitch, it also elevates its commutatorbrushes 127, 128 and 129. As the commutator brush 128 encountersconducting segments 130 oil. the commutator, a circuit is completed forshunting the stepping; relay 302 in the Well-known manner. This circuitmay be traced from ground, con1inututor brush 128, conducting segments1.30 oi the commutator, conductor 181, contacts 132 and 133,1?ight-handttront contact and armature of line relay 115, contact 121, right handwinding of relay 11:23, to grounded battery.

in position t of sequence switch 800 the first ot a series of countingrelays is actu' ated in the Well-known manner to control brush selectionat the district selector snatch. The series of counting; relays is lVhcn the fundamental circuit is intcn rupted, line relay 115 retractsits arinatu and at its left-hand armature and heel: contact completes acircuit for moving switch 100 out of position 3. This circuit may betramid 'lroni grounded battery inn not of sequence switch 100, contact1';- hand back contact and arnuiturc c. 115, lctt-liand bacl; contactand armature oi rcla 114 to ground. In position t oi the cc switch 100the tripping magnet 176 Izod to trip a proper set of l'n'uslics. eziei'ting circuit oi. magnet 17h oxtends from grounded battery, vindf oi?magnet 176, contactl'Z'T, to ground. The

line relay is siniultaneously energized over a circuit extending fromgrounded battery, righthand Winding of line relay 115, contacts 11(3,117, .118 and 119, conductor 120, over the remainder of thelaindainental cir- 7i) irc'viously describi-al. Line relay 115sttractsits armatnrcs and at its left-halal an mature and trout contactcoinpltes a ircuit i'or moving the sequence saith 100 out of LiositiorThis circuit may be traced ductor 193, contacts 12st and i, let -lia=.nltrout contact and armature or. role 11%,

left-hand back contact and armature cl rolay 11 1, to ground. AS theselector elevates brushes, connnututor brush. 129' closes a circuit toshort circuit the stopping relay 3052 through conducting portions 135 oithe conin-iutator, contacts lliand il right in ltll'ill 'lront contactand armature ct relay 115, contact 121, righthaiul i'iiulinp; of linerelay 115, to grounded battery. l lach time that the stepping roluv 302de'eiiicrgizes as a result 0'1 16 (alerting; o'l'f shunt loo circuitdescribed, a pair of counting relays is actuated (in the Wcl.l-k1iown.manner) until the upper zero counting relay 3309 interrupts the:t'undamcntal. ciriit at its outer lejlt-hand bacl; contact and aunituin.

qucnce switchlOO out of position i sition 6. This circuit e t-nds from Fed battery, magnet of sequence sivr A contact 134-, l,....t-h:ind bachcol ct and urinature of M ay 1.15, left and bacl; contact and armatureof relay 1 :o groun T e line relay is an in one-i 1 a cis riglitdiani'lcuit extending; irorn bat winding}; of relay 115, contacts 121 andl'lfl, right-hand lJttChI contact and armature of relay 114;, resistanceto ground. The line relafi at i lc'ft-liand front contact and armaturethen completes a circi l'or nmv' sequence ch 100 into position 7, incircuit extent s from 'roinided battery. inu net of sequence switch. i125, left-hand trout contact and armature 0t 125 relay 115, leiithandback contact i e i-i-z ar 114., to tiiround. an. noted that the testterminals of busy trunk lines are connected to g ound. While thesequence switch 100 is rotating out of pcsi lay 115, left-hand backcontact and armature of relay 114-, .to ground. Commutator brush 127 andcentering commutator segments 140 maintain the relay 115 energized untilthe brushes of the district selector are accurately centered on theterminals of the lected trunk. The energizing circuit oi relay 115 inthis instance extends from grounded battery, contact 184, lett-ha'idwinding of relay 115, commutator sea-me 140, commutator brush I 1.27 toiouud. hen an idle trunk has been found and. the wipers of the selectorswitch have been properly centered on the trunk cm-urinals, the linerelay 115 deenergizes and thereby completes a circuit for moving thesequence switch out of position 7 into position 8. This circuit extendsfrom grounded battery, magnet of the sequence switch. 100, contact 134,left-hand back contact and armature of relay 115, left-hand back contactand armature of relay 114, to ground. The line relay 11f again energizedover a circuit {stablished 'from grounded battery, winding of relay 115,contacts 121 and 138, right hand back contact and armature of relay 114to ground. Relay 115 when energized closes a. circuit from groundedbattery, mag-net of sequence switch 100, contacts 139 and 125, left-handfront contact and armature of re lay 115, left-hand back contact andarmature of relay 114, ground, to move sequence switch into position 11.As soon as the test brush 17 9 engages the test terminal ot the selectedtrunk, the relay 470, Which controls the release of the incomingselector switch 412, is energized over a circuit established fromgrounded battery, winding of relay 470, test terminal 180, test brush179, contacts 181 and 113, right-hand back contact and armature of relay114 to groimd.

In position 11 of the district sequence switch 100, the fundamentalcircuit is extended to the incoming switch shown in the left-handportion of Fig. 4. This circuit extends from grounded battery, windingof line relay 404, contact 403, conductor 402, terminal 145, brush 144,contacts 143 and 119, conductor 120, terminal 229, brush 230,

conductor 232, outer arn'iature and back contact of relay 309, steppingrelay 302, contact 313 of sequence switch 300 (now in position Sconductor 211. brush 233. terminal 231. 7

conductor 11;. contacts 141 and 140. brushes 147, terminal 143,conductor 11f), contact 103 to ground. Line relay 40 attracts itsarmature and thus ConnJletes a circuit for mov ing sequence switch 400out of position 1 into position This circuit. may be traced fromgrounded battery, magnet. of: sequence switch 400, contact 100, troutcontact and armature of line relay 404 to ground. n position of thesequence switch 100 an operating circuit for the updrivc magnet 40? iscompleted from grounded battery. winding magnet 40?, contact 408. frontcon-- tact and armature on? relay lot to ground. As the selector 412elevates its brushci i. the cou'nm'ltator brush 100 encounters conducbing segments 410. The line relay ifil is inaiiitained energized and thestepping relay 302 is shunted over a circuit extending from groundedbattery, winding ot relay 104. cons tact 411, conducting se 'nents 4-10,commutator brush 409 to ground. For each conducting segment 41.0encountered by the coinmutator brush 409, a pair of counting relays isactuated to control the brush selection at the incoi'ning switch. lVhenthe series of counting relays has been actuated. the relay 309 attractsits armatures and the l'uudamental circuitis intcrriu ted, causing theline relay 404 to de'energize. This couspletcs a circuit for moving thesequence switch 400 out of position 1 into position which circuit may betraced from arounded battery. magnet of sequence switch 100. contact413, back contact and armature ol" line relay 404 to ground. In position2-. of the sequence switch 400 the brush tripping magnet 414 isenergized over a circuit extending from grounded battery. winding oftripping magnet 414. contact 4 15 to ground. The 'lundamental circuit isagain rcfistahlished and the line relay 404 attracts its an mature toagain close. the operating circuit of the up-drive magnet. \Vhen new thebrushes oi? the selector switch 412 are again elevated, thecommutatmbrush l0!) encounters a conducting segment 410 for each roupassed by the switch. Each time that thc con'nnutator brush encounters aconducting segment 410, line relay 401 is maintained energized andstepping clay 302 is short circuited to actuate a pair of countingrelays in the manner indicated. \Vhen thc scricof counting relays isagain actuated to energrize the upper zero counting relay t-WL thefundamental circuit is interrupted, calr-zing the line relay 401- toretract its armature. This closes a circuit from grounded battery.magnet of sequence switch 400. contact 113, back contact and armature ofrelay 109 to ground, to move the sequence switch out 0'!" position 4. Itis assumed that the selector switch 412 will now hunt for an idle trunkin the selected group. This operation, howliit) 1 ,ae naov ever, is notdescribed. since itie now wellknown in the art. When the brushes 417, noand. H9 have been placed in engagement with the terminals 530 4:121 and422 of the selected trunlsz, the fundamental circuit is extended to thedeal selecting switch. is energized over a circuit ere i in groundedbattery, e iiiiding of relay 1:23, terminal brush 1119, contact in r toground, to prevent the relcaee of the final switch until the incoming'switch has been restored to normal position. When the lundainientalcircuit extended to the final iotitch orer the contacts 425 and 4:26,the line relay l i]? is energized and attracts its armature. Thiscompletes a circuit :t'or moving the sequence switch out of position 1and into position lit position 2 oi? the Sequence switch i529 the urdrive n'iagnet e130 become. energized Ottllf a circuit extendin fromgrounded l tiler m Winding; of on root 430 contact 4131 it t contactand. armature oi line relay to nund. The final selector switch 2elevates its hrushee 4l-3l, 434 1:35 and also elevates; thecolnniuitator brushes 4-30, Tlhc in'ush 4 ;36 enco'lnrtere theeond1u-t-- iior'tione :37 and i li of the connnntator and thehrueh 4:80encountere the con-- dnctin r portions 4:50 and i l-O. AS the lunch 4556encounters the conducting s 7 the line relay ift? is maintainer i iaedand the eteppingrelay 302 short circaited by a circuit extending; tronI3 qrmindod battery, Windingof relay .1127, con

i391 conducting segments i137 connnnbrush e o to ground. This ehunto thesteppi relay actuatee the chain relays to determine the brush at thefinal selector switch. When l in o counting; relay 309 actuatt-ith thei'innlaniental circuit in again interrupted to route the deenergizationof the line relay llliis coinpletee a circuit from ground ed hattcmagnet of sequence switch 4-99w contact contact and armatime oi: lineround to more sequence 3. The tundanien- H 'ablishcd and the linearniatom thereby coinin inn; the circuit for moving: the sequence -h outi DUIL-l'ltlOD 3; This circuit tron i tery, magnet oi eeoiicire ct 4.28,t'ront con tact and arm a 42'? to ground *ition 1 nice switch 429, theupa i i in one iced over a circuit i grounded hetter n winding ol'contact 41:31, troi ay il-917 to ground. gain elevates ite- .1eeg, whichcans-are the connnutator hrne 486 to on age the minthicting segmentsii-.1. oi the -:*onfninutatoi to control the group sent lection oi? theswitch. As the brush 41-36 onl H 2. l

iii

countere a conducting segment ill for each group of truults pained over,the stepping ie el'iort .li'CllflllQtl to actuate the counting); relaysl'l ltien the series of counting relate; have heen actuated and thefundamencircuit again opened, the line relay 4:27

' it circuit now completed n o tor magnet oi? te ucnce a tch min'tact4:0, back contact and arinatni of relay to ground, to more theeequi-nice switch out of position 5. The fundamental circuit is againrecstahliehed h the resultant encrgizationoit the line re e27. A circuitis thereupon completed for l'iiOVjllIfI the aequence twitch J into position 6. 'lliie circuit extends t: in grounded battery, magnet o'l.sequence enitch 4129 contact licit rt contact and arnnttnrc' oi.

art relay 427, to ground. In pos'tion 6 the updri've magnet e30 is agrain energized over a t extendh from grounded battery, winding; ofmagnet 4530, contact l-i'll, front continrt and armature of re 427. Theiinal seiector switch 4-352, again elevates its hrushee, and thecommutator brush i236 en-' put, an opera inn: circnit is completed forthe aquence swi'ch 300, which circuit or;-

tende tron'i grounded battery, magnet 01E quence switch 300 frontcontact and inner orniatlu'e olfrelay 309, contact 311, toground. At theclone of the units series of in pulses, when the .elay 305i attrants ito arinatures to complete the circuit just described, the so nienceswitch 300, which in the operation of the sende" has been ad vanced toposition it, new moves out of this; position and under the control oi.its inaction route ct moves; into position 1,

l ihile the sequence switch is rotating; through peeitione 17 and 18, acircuit is conr pleted tronir ground, contact 312, conductor $51G,nnrgggnet of sequence switch 200, to 'rounded battery, to move thinsequence ch out oi position at and into iiosition in porn ion 8 ofsequence {Ni 11 9100, acir- (Mill is completed from ground contact brush236 terminal M7, conductor 223, contact 185i magnet of sequence switch100 to grounded battery, to more the sequence switch out oat position11. into poeition l2 lWlv-in the SL mince switch 100 moves; out ofpetition ii. the energizing circuit oi" the relay E219 interrupted atcontact he soon the sequence switch 300 reaches tact 240 to ground.

. The sequence switch 100 isadi position 1 a circuit is completed forthe down-drive magnet 238, which circuit cxtends from grounded battery,winding of magnet 238, conductor E239, contact 317, con- As soon as thecord finder 220 reaches its normal.position, a circuit is closed fromground, commutator brush 2-11, conducting segment A2 of the commutator,conductor 243, contact .2491 magnet of sequence switch 200 to groundedbattery, to move this sequence switch out of position 8 into its normalposition. The cord finder and the sender are now in condition foroperation in completing another call. need through positions 12 and 1;ntoposi u 1- over a circuit completed trom groi :ed battery. magnetofsequence switchlOO, contacts 180 and-187, hack contact. and armature ofrelay 158 to ground. Under the control of its master contact 191sequence switch 100 rotates intov position 15. Immediately after thedcenergization ot line relay i and while the sender and cord 'finder arebeing restored to their normal position and While the sequence switch100 is being advanced to position 14-, a circuit is completed fromground, armature and back contact of this relay, contact 4 .10, windingof sequence switch $29 to grounded battery. The sequence switch 429 isthus moved out oi? position6 and continues to rotate until. it reachesposition 11. lYhen the sequence switch 429 is rotating through positions8 to 14, if the desired line is busy, this condition will be indicatedby reduced potential on its test terminal ii 'lcaused by another finalselector in connection with the line. The test relay 4.4.6, whichismarginal, will not be energized in the test circuit which may be tracedfrom grtnuuled initteiw', resistance, terminal .44:, brush 05, contactHT. through both windings in series oi" relay 4413 to ground. lVhen thesequence swil ch -29 reaches position 14, with test relay 44odeenergized, a. circuitis completed t'rom grormd,left-hand armature andback contact of test relay 146, contacts +tS1 and +17 winding ofdown-drive magnet M9 to g inded battery.

When the commutator brush 1'80 encounters the conducting segment a circuit is completed from ground through this commutator hrush andcoi'nlucting segment. contact 1-57, magnet of sequence switch 429 togroundedbattery, to more the sequence switch out of position 11 and intoposition 17. In position 17 of the sequence switch 429, an interrupter,generally designated 452, is connected to contact to control theactuation of a. signal at the oftice in which the call originated;

In the present description the call has been extended to a subscriberwhose telephone line terminates in the same OlliCQ as the callmg line.At the upper portion of Fig. 1-.

there diagrainma-ticall indicated wilhiz: the dotted rectangle, thetrunk lines and incoming and final selector switches through which thecall may be extended to a distant ofiice.

In accordance with the present inw-utiml, it it is found that thedesired line terminating in the same ol'lice is busy, it is desired loindicate this fact to the maerator. It the desired line at a distantoflice is busy, it is desired to give the operator a different sig nalto inform her of this condition. For this purpose it is proposed toemploy the signal lamps 150 and 151 to perform these functions. In theformer systems the lamp 150 serves as the calling supervisor signal. andthe lamp 151 flashes until the sender has been disconnected from thecord with which it is attached, but burns stcadily to indicate that thecalled subscriber is heing rung, and is immediately extinguished as soonas the called subscriber answers. In addition to theseindicatingoperations it is proposed to light lamp 151 to indicate when adesired line that is busy, terminates in the local exchange, and tolight tho lamp 150 to indicate when a desired busy line is at a di. tantexchange. This indicating operation is employed in distinguishingso-callcd re vertive calls.

For the control of the lamp signals Ito and 151, two interrupters andliilare employed. It is thought that the de crip tion of interrupter 452will he sullicicnt 'l'or a clear uuderstant-ling oi the interrupter 151.The interrupter 152 comprises a constantly rotating, shaft 455, on whichthere are mounted disks 456, 1.77 and 458. The dial; 456 is formed ofconducting material, but its surface provided with uni ormly Spacedinsulated portions which serve to interrupt the circuit through thebrush 4-59. The disk 457 is also formed of conducting material. but itsperiphery. with the exception of conducting portion 460, is covered withinsulal ing material. Disk 458 is similar in construction to disk 4-57,but its conducting portion 461 is so positioned that, the circuittending through its brush 162 not completcd until the circuit extendingthrough the conducting portion 1-60 and l 'ur-ih has has beeninterrupted. The intcrrimter 15 i is preferably constructed to interruptits ci r cuits in different time intervals from the intcrrupter 152.

In position 1'? of thc seqimuce switch lit) a flashing circuit iscompleted from ground through the disk 1:50, brush +59, contact 15:,terminal 12], brush +13, contact (54, conl .ctor 1&4), terminal 14-8,brushes H7. contacts 146 and 152, superrisor relay 153. winding o't'repeating coil to grounded baticr Since this circuit is alternately openand closed at the disk 456 and brush lffl.

the supervisory relay 153 vibrates its armatill lllll llll llfll lIHitore. When the relay 153 ettrects its armaa circuit is completed fromground, fr it rentact and armature of relay 1558, contract 1855',righthand Winding; Oil: relay lift to grounded l'attery. The relay 115at its right-hand front contect and armature mmtrols a brcalepoint inthe circuit extending; trom ground through conducting portion tee oi":the disk 4e56, brush 4:63, conductor 4:65. contact 154, righthen Frontin l lzi'li'lttljllltj of relay 115, con.- W5 contacts 156 and 157,winding oi? relax 158 to grounded battery. The relay H5, at itsright-hand back Contact and :nrwature controls a lJl'GiilI-Pflllllt inthe circuit extending from ground, conducting our N31 oi? the di 4:58,brush 4-62. con- (lll l'tfil' MSG, Contact loll, right-hand heck contactand armature of relay 115 contit e? to grronnded battery. It should 9rrler 158 is not eitiergited ,r:ttir ,,g circuit for moving :witcli 100out of position He i line terminates et the local -i trolled by theinterrupter portions oi. the dis a a rrarnged that the cir a it +9 68and "39 are not closed For tlii, reason, when the attracts its armatureto 115, the circuit E rough x the right-hand front 001% It will be openet the brush i 1 ct H?!) are so h hrn i I moot ely.

1", that Elie relav 1L5 deenergi'nee, extending; to m: grounded bat rele'38, cintacts 157 end lire, & ht--l and arn'iature and 115 contacts 159and i :58 to ground will be which at this time igegenl ent Wi tlr con dn eti ng and 4158 it will thee be r 1v r n 1 tn ltd rill) 111 Retail (lexchange the will i he :--"oqne.e.ce ch 100 r "on 15 antil the opt-Waterredo; 5) from the jact: of the toll,-

.. i. will. lie cloeed For The circuit e ends r r em grounded. nip loll,*L..

r w r isle-lance tl. re e g1:

J-liand heck contact and arinejtmfc o'l relay 114- to the celled linerline terminates; at it oiliee the interrupter -45: will con ei'ier-ation of the snpe v sory ren a l wry lay lee.

This controlling; circnr will extend from ground, disk 468 brush 1:69,concon units 156 and 157, Winding" doctor 4:67, the terminal and brush4.80 of the incoming selector switch at the d'stant o'i'lice, conductor1:81 terminal 192 and brush 14-7, contacts 146 and 1521, winding of thesupervisory relay 153, winding; of the re eating coil to groundedbetter-y. In this case the energizin circuit tor the relay 158 iseon'ipleted follows: The eepervisory relay 153 is 'ensel to rib 'ztteite arniatnres by it circuit extending}; from ground, disk L68 and brushtee of interrupter iS-i, contact 48 conductor 41:67, brush i530 of thetwining switch at the distant ollice, connctor e81, terniinnl 192hrushee 147 o'lf the riot selector 1336 contacts lei-6 and 152 relay1653 to groemled battery. its pre- 'l'llll sly steted the interrupter tbreaks the circuits which it controls in (litter-nit tin'ie tlfi:t'ron'i the interrupter The i d. (l

lay 115, causing; his line relay to close, at,

its right-lewd animal-erg hrealr points in eomlnctore M35 and 166, atthe same time that the other break poin s in these conductors are closedat interrupter 452. Belay 158 energized over either of conductors i655and =l66 and attracts ite armature. A circuit is tiereley closed tormoving the ecquence switch 100 out of position 15 into position 16. Thiscircuit may be traced troin grounded battery, magnets of sequence switch100, contacts 139 and 164:, front conlect and armature oi. the relay 158to grronnd. In prsition 16 e ci 'cnit is closed for ileehinn; the lamp150 until the operector removes p 1.09 from jack 110. This circuit isestablished from grounded bflllllfly, l'(}l-"li5iit!l00, the lamp 150,Contact 165, left hand beet: .ontact end arn'iature of relay 13. ii'-l'!itn{l arm: ture and back eontactot ie relay 114- to gifiillltl.

When the opemtor removes the plug 5) from the jack ".0 oi? thecafllingrline, and 1 leproeses r trout lmy Ede the relay .ES energ iemin the circuit extending romgronnded he Y llal attracts its ht-handarineture winding of relay 1. l,

meta e l a n d arm rrtnre oil ti. relay l'l l rte Vermeer to ground. Atthe let't-iianrl armature en contact of this relaya circuit is ct: d:lroin o round, contact 169, magnet end til- Hence rm itch .100 togrounded battery, to a the sequence switch from the position in which itis then at rest, tent is either partition 15 or ltt into position 18. inno H1 18 oil the sequence switch 160 an encr cling circuit for thedown-drive magnet W0 is completed tlrore jt'tOtlltlGtl battery windingof magnet 1 .70, umtacts 171. and to ground. When. the

eve

e-out key V grounded ljiattery, concommutator brush 129 encounters thenormal conducting segment 173, a circuit is closed from ground throughthis commutator brush and contact, conductor 17 at, contact 17.5,sequence switch 100 to grounded battery. This circuit causes thesequence switch to rotate inte position 1. When the relay lltattractsits right-hand armature it opens the energizing circuit of the relay 470(Fig. 4t). This relay retracts its armature and completes a circuit fromground, through contact 4:71. magnet of sequence switch 400 to groundedbattery, to move this through armature and back contact of the relay423, contact 476, magnet of sequence switch 129 to grounded battery, tomove the sequence switch into position 18. In position 18 a circuit iscompleted for the downdrive magnet el-lQ, which circuit extends fromgrounded battery, winding of magnet 449, contact 477 and $78 to ground.Vhen the final selector switch is restored to its normal position acircuit is closed from ground, commutator brush 180, normalconductingsegment i450, conductor $79, contact i557, magnet of sequenceswitch 4:29 to grounded battery, to move this sequence switch into itsnori'nal position.

What is claimed is:

1. In a telephone exchange system, a plurality of lines, a plurality ofoflices through which certain of said lines may be interconnected, twosignals at one oi. said oflices indicating the electrical condition ofsaid lines, only one of which signals operates during a complete call,means at said last mentioned oliice which cooperates in controlling theoperation of one of said signals, means at another oflice whichcooperates in controlling the actuation of the other signal, and anautomatic device for controlling the operation of both of said signals.

2. In a telephone exchange system. a plurality of lines, a plurality ofoliices through which said lines may be interconnected. two signals atone ofsa-id offices indicating the electrical condition of the lines,only one oi which signals operates during a complete call, aninterrupting device at said oflice which. cooperates incontrolling theoperation of one of said signals, an interrupting device at the otheroilice which cooperates in controlling the actuation of the othersignal. and a device at the first mentioned ollice for controlling theoperation 0:! said signals.

In a telephone exchange system, a plul'ililtj. oi lines, a plurality oioilircs through which said lines may be intcrcmmectcd, two signals atone of said oiliccs indicating the electrical condition of the lines.only one oi which signals operates durin a complete call, aninterrupting device at said oilicc which cooperates in controlling theoperation (it one of said signals, an interrupting device at the otheroiiice indepemlcnt o i said first mentioned interrupting device whichcooperates in controlling the actuation of the other signal, saidinterrupting devices operating out of synchronism, and a device at thefirst mentioned oiiice tor controlling the operation of said signals.

i. In a telephone exchange system. a plurality oi lines, a plurality oioflices through which said lines may be interconnected, two signals atone of said oiiices indicating the electrical condition of the lines, acontinuously operating interrupting device at said oillco whichcooperates in controlling the operation of one of said signals, aninterrupting device at the other oilice independent of said firstmentioned interrupting dc- Yice, which cooperates in controlling theactuation of the other signal, and a circuitcontrolling device at thefirst meutirmcd oilice for controlling the operation of said signals.

In a telephone exchange system, a plurality of lines, a plurality ofoliices through which said lines may be interconnected, two signals atone of said oilices indicating the electrical condition of the lines, acontinuously operating interrupting device at said ofiice forcontrolling the operation of one of said signals, an interrupting deviceat tho other office independent of said first mentioned interruptingdevice for controlling. the actuation of the other signal, and anauxiliary switch at the first mentioned oilicc for controlling theoperation of said signals.

6. In a telephone system, a primary ofiicc. a secondary oiiice, linesteri'ninatiug in each of said oiiices, an incoming line, means forextending said incoming line through said primary oiiice to any of saidlines, means for rendering any of said lines husy, auto matic means atone of said. olliccs for indi cating that a busy line terminates at theprimary oflicc, and means at the same oilicc for indicating that a busyline terminates at the secondary office.

7. In a telephone system, a primary ollicc. a secondarv oflice, linesterminating in each oi said ofiiees, an incoming line, means forextending said incoming line through said primarv oiiice to any of saidlines, means for rendering any of said lines busy, automatic means atthiprimary oflice for indi.

eating that a busy line terminates at the primary oflice, and automaticmeans at the same oflice for indicating that the busy line terminates atthe secondary oflico.

8. In a telephone system, a plurality of lines, a plurality of otficesthrough which said lines may be interconnected, means for rendering anyof said lines busy, two signals at one of said oiiices for indicatingthe character of said busy lines when called lines, a device forcontrolling the operation oi either of said signals, and means forcontrolling the operation of said device.

9. In a telephone exchange system, a plurality of lines, a plurality ofoiiices through which said lines may be interconnected, means forrendering any of said lines busy, two signals at one oi said oflices forindixating the busy or idle condition of said lines, a device at saidlast mentioned ofiice tor controlling the operation of either of ea idsignals and a continuously operating device at each of said offices forcontrolling said device.

10. In. a telephone system, a primary oliice, a secondary ofiice, linesterminating in eacl'i of said offices, means for interconnecting any ofsaid lines with any of the remaining lines, means for rendering any ofsaid lines busy, a signal at one of said o'iiices for indicating that abusy line terminates at the primary oflice and a signal. at the sameoliice for indicating that a lousy line terminotes at the secondaryoiiice.

ll. In a telephone system, a primary oilice, a secondary oiiice, linesterminating in each of said oflices, means for interconnecting any ofsaid lines with any of the re maining lines through said primary oliice,means for rendering any of said lines busy, signals at the primaryofiice for indicating at which of said otiices the busy line terminates,a device at said primary oflice for controlling theactuation of eitherof said si nals, and mechanism at each of said oflices for controllingthe actuation of said device. y

12. In a telephone system, a primary office, a secondary office, linesterminating in each of said offices, means for interconnecting any ofsaid lines with any of the remaining lines through said primary otiice,means for rendering any of said lines busy, signals at the primaryoflice for indicating at which of said oflices the busy line terminates,a device at said primary office for con trolling the actuation of eitherof said sig nals, and a constantly operating mechanism at each or saidoffices for controlling the actuation of said device.

13. In a telephone system, a pluralit of: lines, a plurality of officesthrough wiich said lines may be interconnected, means for rendering anyof said lines busy, two signals at one of said offices for indicatingthe character of said busy lines when called lines, a device forcontrolling the operation of either of said signals and timing mechanismat each of said oflices for controlling the operation of said device.

14. In a telephone system, a plurality of lines, a plurality of oflicesthrough which said lines may be interconnected, means for rendering anyone of said lines busy, two signals at one of said oifices forindicating the character of said busy lines when called lines, a devicefor controlling the operation of either of said signals and a timingmecha nism at one of said offices and means at the other ofiice forcontrolling the operation of said device.

15. In a telephone system, a plurality of lines, a plurality of oflicesthrough which said lines may be interconnected, means for rendering anyof said lines busy, two signals at one of said ofiices for indicatingthe character of said busy lines when called lines, a device forcontrolling the operation of either of said signals and timingmechanisms operating out of synchronism with respect to each other,located at each of said ol'iices for controlling the operation of saiddevice.

16. In a telephone system, a plurality of lines, a plurality of oflicesthrough which said lines may be interconnected, means for rendering anyof said lines busy, two sig nals at one of said offices for indicatingthe character of said busy lines when called lines, a device forcontrolling the operation of either of said signals and timingmechanisms remotely located with respect to each other for controllingthe operation of said device.

.In witness whereof, I hereunto subscribe my name this 28th day ofDecember, A. D.,

ALBEN E. LUNDELL.

